With regard to elderly relatives one would take the same precautions as in previous years ie with colds, flu etc. However, it may need to be balanced against someone who, for example, hasn’t seen or spoken with anyone over the last week, fortnight, month etc. Human contact is so important and only you can decide whether any type of risk is appropriate.
As @Bunnyhop states, washing hands is important as well as using a tissue to cough and then dispose of right away. Basic stuff and common sense.